Ultrasound sclerotherapy is similar to conventional sclerotherapy. The difference is that the doctor has a monitor on which he can visually see veins that cannot be seen with the ordinary eye. This means that he can find hidden veins beneath the surface of the skin and eliminate them with greater accuracy and precision. The procedure is also considered safer for treating very large veins. During the sclerotherapy treatment a liquid is injected directly into the veins, causing them to contract and collapse. Over time, the veins fade from view.